Frequency of sex chromosomal disomy in spermatozoa of normal and oligozoospermic Iranian patients and its effects on fertilisation and implantation rates after ICSI

Chromosomal aneuploidy is a well‐known phenomenon in human gametes including spermatozoa. Success rate of fertilisation and implantation in subfertile patients with male factor has always been shown to be very low. We tried to relate the possible impact of sex chromosomal aneuploidy in spermatozoa used for intracytoplasmic sperm injection (ICSI) on fertilisation and implantation rate. To evaluate the frequency of disomy for X and Y chromosomes in sperm samples retrieved from normal and oligozoospermic individuals, primed in situ labelling (PRINS) technique was used. Following ICSI, the rate of eight‐cell embryos for each category was determined and followed up for successful implantation. Results showed a statistically significant higher frequency of disomy for all chromosomes under study in spermatozoa of oligozoospermic patients compared with normal men (P < 0.01). The rate of eight‐cells embryo formation was significantly lower than in normal group (P < 0.01). The number of embryos transferred for both groups were nearly similar. Implantation rate for oligozoospermic patients was much lower than that of the normal group but was not significantly different (P > 0.05). These results demonstrate that men especially with severe oligozoospermia have an elevated risk for chromosome abnormalities in their spermatozoa. These abnormalities might affect fertilisation and pre‐embryo formation with less impact on implantation.     

N‐acetyl‐L‐cysteine pre‐treatment protects cryopreserved bovine spermatozoa from reactive oxygen species without compromising the in vitro developmental potential of intracytoplasmic sperm injection embryos

Excess of reactive oxygen species (ROS) on in vitro embryo production systems negatively affects the quality and developmental potential of embryos, as result of a decreased sperm quality and increased DNA fragmentation. This issue is of major importance in assisted fertilisation procedures such as intracytoplasmic sperm injection (ICSI), because this technique does not allow the natural selection of competent spermatozoa, and therefore, DNA‐damaged spermatozoa might be used to fertilise an egg. The aim of this study was to investigate a new strategy to prevent the potential deleterious effect of ROS on cryopreserved bovine spermatozoa. We evaluated the effect of a sperm pre‐treatment with different concentrations of N‐acetyl‐L‐cysteine (NAC) on ROS production, viability and DNA fragmentation and assessed the effect of this treatment on the in vitro developmental potential and quality of embryos generated by ICSI. The results show a strong scavenging effect of 1 and 10 mm NAC after exposure of spermatozoa to a ROS inducer, without compromising the viability and DNA integrity. Importantly, in vitro developmental potential and quality of embryos generated by ICSI with spermatozoa treated with NAC were not affected, confirming the feasibility of using this treatment before an ICSI cycle.     

Gradient sperm selection for reproductive techniques in cattle: Is Isolate a suitable replacement for Percoll?

In assisted reproductive techniques, it is essential to perform a sperm selection to obtain spermatozoa with high motility and membrane integrity for in vitro fertilisation (IVF) and high‐DNA integrity for intracytoplasmic sperm injection (ICSI). In this study, we evaluated whether Isolate ^® was a suitable substitute for Percoll ^® for assisted reproductive techniques. Commercial cryopreserved bovine semen was used after selection in both gradients, and plasma and acrosome membrane integrity, reactive oxygen species (ROS) levels, DNA integrity and mitochondrial membrane potential (ΔΨm) were assessed by flow cytometry. Motility parameters were also evaluated by CASA system. A similar percentage of spermatozoa with intact plasma membrane, acrosome integrity and high ΔΨm was observed in both sperm selection methods, but only Percoll ^® showed higher percentage of spermatozoa with intact plasma and acrosome membrane compared to the post‐thawing group. No differences were observed in the motility, ROS, DNA fragmentation and on the in vitro embryo production in all experimental groups. In conclusion, the selection of bovine spermatozoa with Isolate ^® generates spermatozoa with similar quality parameters and embryonic development compared to Percoll ^® providing a suitable alternative sperm selection method for assisted reproductive techniques in this species.     

Moderate‐intensity exercise training ameliorates the diabetes‐suppressed spermatogenesis and improves sperm parameters: Insole and simultaneous with insulin

The current study was conducted to investigate the ameliorative effect of moderate‐intensity exercise training insole and simultaneous with insulin on diabetes (DM)‐induced pathogenesis at the testicular tissue and sperm level. For this purpose, 36 mature male Wistar rats were divided into six groups, including sedentary control (Con), exercise training (EX), sedentary experimental DM‐induced (SDM), exercise training + DM‐induced (DM + EX), insulin‐treated sedentary DM‐induced (DM + INS) and exercise training and insulin‐treated DM‐induced (DM + INS + EX) groups. Following DM induction, the 6‐week exercise training intervention (30 min of moderate‐intensity running on a treadmill, once daily [5 days/week]) was considered in EX groups. The tubular differentiation (TDI) and spermiogenesis (SPI) indices, testicular total antioxidant capacity (TAC), superoxide dismutase (SOD) and glutathione peroxidase (GPX) contents, serum testosterone and insulin levels, the apoptosis ratio and sperm parameters were assessed. The exercise in sole (EX) and simultaneous forms with INS (DM + INS + EX group) ameliorated the DM‐suppressed spermatogenesis and spermiogenesis indices, up‐regulated the serum testosterone and insulin levels, enhanced testicular SOD content, inhibited the apoptosis and improved almost all sperm parameters. In conclusion, exercise training, when simultaneously considered with insulin, fairly boosts the insulin‐induced impacts, including the up‐regulated testicular endocrine and antioxidant status, spermatogenesis and sperm quality.     

Additional deleterious effects of alcohol consumption on sperm parameters and DNA integrity in diabetic mice

The aim of this study was to survey the impact of alcohol consumption on sperm parameters and DNA integrity in experimentally induced diabetic mice. A total of 32 adult male mice were divided into four groups: mice of group 1 served as control fed on basal diet, group 2 received streptozotocin (STZ) (200 mg kg^?1, single dose, intraperitoneal) and basal diet, group 3 received alcohol (10 mg kg^?1, water soluble) and basal diet, and group 4 received STZ and alcohol for 35 days. The cauda epididymidis of each mouse was dissected and placed in 1 ml of pre‐warm Ham's F10 culture medium for 30 min. The swim‐out spermatozoa were analysed for count, motility, morphology and viability. Sperm chromatin quality was evaluated with aniline blue, toluidine blue, acridine orange and chromomycin A3 staining. The results showed that all sperm parameters had significant differences (P < 0.05), also when sperm chromatin was assessed with cytochemical tests. There were significant differences (P < 0.001) between the groups. According to our results, alcohol and diabetes can cause abnormalities in sperm parameters and chromatin quality. In addition, alcohol consumption in diabetic mice can intensify sperm chromatin/DNA damage.     

Royal jelly protects male rats from heat stress‐induced reproductive failure

Royal jelly (RJ) as an antioxidant has been shown to have attenuated oxidative stress damages in reproductive organs. The objective was carried out the effects of RJ on sperm characteristics, sperm malondialdehyde (MDA) concentration and in vitro fertilisation (IVF) outcome in heat stress (HS) exposed male rats. Forty‐eight male rats were randomly divided into eight groups; group 1 received normal saline, group 2 received RJ (100 mg kg^?1 day^?1; PO), groups 3, 4 and 5 were heat‐stressed (43, 39 and 37°C for 20 min per day respectively) and groups 6, 7 and 8 were heat‐stressed along with RJ (43, 39 and 37°C for 20 min per day, respectively, plus RJ at a dose of 100 mg kg^?1 day^?1; PO). The HS was induced through immersion of experimental rat scrotums in a water bath. After 48 days, the HS induced remarkable diminish in sperm motility, viability and fertilising potential along with reduced blastulation rate and enhanced sperm chromatin abnormality, MDA levels and DNA damage. Nevertheless, RJ co‐administration improved sperm characteristics and early embryo development as well as sperm lipid peroxidation level. Our data suggest that RJ can effectively ameliorate the experimental HS‐induced infertility in rats through MDA concentration restoration and sperm characteristics and pre‐implantation embryo development improvement.     

Accurate sperm morphology assessment predicts sperm function

Sperm morphology has been associated with in vitro as well as in vivo fertilisation. The study aimed to evaluate the possible relation between the percentage of spermatozoa with normal morphology and the following sperm functional assays: (i) zona-induced acrosome reaction (ZIAR); (ii) DNA integrity; (iii) chromatin condensation; (iv) sperm apoptosis; and (v) fertilisation rates. Regression analysis was employed to calculate the association between morphology and different functional tests. Normal sperm morphology correlated significantly with the percentages of live acrosome-reacted spermatozoa in the ZIAR (r = 0.518; P < 0.0001; n = 92), DNA integrity (r = -0.515; P = 0.0018; n = 34), CMA(3) -positive spermatozoa (r = -0.745; P < 0.0001; n = 92), sperm apoptosis (r = -0.395; P = 0.0206; n = 34) and necrosis (r = -0.545; P = 0.0009; n = 34). Negative correlations existed between for the acrosome reaction, and DNA integrity, while negative associations were recorded with the percentages of CMA(3) -positive spermatozoa, apoptotic and necrotic spermatozoa. Sperm morphology is related to sperm dysfunction such as poor chromatin condensation, acrosome reaction and DNA integrity. Negative and significant correlations existed between normal sperm morphology and chromatin condensation, the percentage of spermatozoa with abnormal DNA and spermatozoa with apoptotic activity. The authors do not regard sperm morphology as the only test for the diagnosis of male fertility, but sperm morphology can serve as a valuable indicator of underlying dysfunction.     

Evaluation of the morphokinetic parameters and development of pre‐implantation embryos obtained by testicular,epididymal and ejaculate spermatozoa using time‐lapse imaging system

Low sperm quality has negative effects on fertilisation and embryo development. The males with azoospermia apply for testicular sperm extraction (TESE) or microsurgical epididymal sperm aspiration (MESA) in order to retrieve sperm. To date, there have not been any reports investigating morphokinetic parameters of pre‐implantation embryos using testicular and epididymal spermatozoa. Therefore, we aimed to correlate embryo development and assess morphogenetic parameters in embryos obtained by TESE and MESA using time‐lapse imaging. A total of 60 patients undergoing IVF treatments were included in this study. Twenty men with normal semen parameters were selected as control group. Twenty men undergoing TESE and 20 men undergoing MESA were also included in this study. The morphokinetic parameters of time intervals between the second polar body (PB2) extrusion, pronuclei formation and disappearance and cleavage divisions showed significant variations in TESE, MESA and control groups. Furthermore, the pregnancy rates (positive beta‐hCG) were shown to be similar in both TESE and the control group (55% in each group), whereas for the MESA group, this rate was significantly lower (39%, p = 0.049). Further extrapolation of these results may implicate that the obstructive azoospermia patients should undergo TESE instead of MESA for better blastocyst development and higher pregnancy rates.     

Use of Raman spectroscopy to identify active spermatogenesis and Sertoli‐cell‐only tubules in mice

Microdissection testicular sperm extraction (micro‐TESE) has become the first line therapy to harvest spermatozoa for men with nonobstructive azoospermia. However, the pitfall is that the selection of seminiferous tubules depends on subjective assessment of the colour and size of tubules, which cannot guarantee successful retrieval of spermatozoa. The aim of this study was to determine whether Raman spectroscopy (RS) could distinguish tubules with spermatogenesis from Sertoli‐cell‐only (SCO) tubules, and potentially serve as a useful tool to improve sperm retrieval rates. Fourteen male adult mice were divided into two groups: SCO group received a single intraperitoneal injection of busulfan (40 mg per kg body weight), and the control group received a placebo dose of 0.9% saline solution. Mice were sacrificed after 4 weeks, and the testicular tissue was assessed by RS and then confirmed with histopathology. The results indicated that tubules with spermatogenesis had intensified Raman peaks at 748, 1124, 1309, 1446 and 1658 cm^?1 compared to SCO tubules, except a decreased peak at 1582 cm^?1. RS was able to distinguish the two groups with a sensitivity of 91.2% and specificity of 82.9%. In conclusion, RS may serve as a useful diagnostic tool prior to sperm retrieval.     

Proper ubiquitination effect on the fertilisation outcome post‐ICSI

Ubiquitin is an 8.5‐kDa protein that tags outlived proteins for degradation by the proteasome. It also marks defective spermatozoa during epididymal passage and has been proposed as a biomarker of sperm quality. This study evaluates the relationship between sperm ubiquitination, protamine deficiency, semen parameters and fertilisation rate in infertile individuals undergoing the intracytoplasmic sperm insemination (ICSI) procedure. Semen samples from 73 ICSI candidates were collected and analysed according to World Health Organization criteria. A portion of each sample was evaluated for sperm ubiquitination using the sperm ubiquitin tag immunoassay (SUTI) with flow cytometry, and protamine deficiency by chromomycin A3 (CMA3) staining. In addition, the relationship between the fertilisation rate and sperm ubiquitination was calculated in ICSI candidates. The intensity of ubiquitination showed a significant negative correlation with sperm concentration (r = ?0.255, P = 0.032) and a positive correlation with fertilisation rate (r = 0.384, P = 0.013) post‐ICSI. No correlation was observed between protamine deficiency and the percentage of ubiquitination or ubiquitination intensity. The results of this study suggest that sperm ubiquitination prior to capacitation may be considered as a marker of defective spermatozoon. Spermatozoa that undergo proper ubiquitination may have a higher chance for fertilisation, because they are made redundant by the ubiquitin–proteasome pathway in the epididymis compared to hypo‐ubiquitinated spermatozoa.     

Association between total globozoospermia and sperm chromatin defects

Globozoospermia is a severe sperm morphological anomaly leading to primary infertility and low fertilisation following intracytoplasmic sperm injection (ICSI). This phenotype is observed in less than 0.1% of infertile men and is determined by small, round‐headed spermatozoa with absence of an acrosomal cap, acrosome protease and also cytoskeletal proteins. Failure of oocyte activation is considered as the main cause of fertilisation failure in these individuals post‐ICSI. Therefore, artificial oocyte activation (AOA) along with ICSI is commonly implemented. However, based on previous report, fertilisation rate remains low despite implementation of ICSI‐AOA. Therefore, other mechanisms like sperm chromatin packaging and DNA fragmentation may account for low fertilisation and development post‐ICSI‐AOA. Therefore, this study aims to assess and compare the degree of sperm protamine deficiency and DNA fragmentation in large population of infertile men with total globozoospermia (30 globozoospermic men presenting with 100% round‐headed spermatozoa) with 22 fertile individuals using chromomycin A3 and TUNEL assay respectively. Results clearly show that mean of sperm concentration and percentage of sperm motility were significantly lower, while percentage of sperm abnormal morphology, protamine‐deficient and DNA‐fragmented spermatozoa were significantly higher in infertile men with globozoospermia compared to fertile men. Therefore, increased sperm DNA damage in globozoospermia is likely related to defective DNA compaction and antioxidant therapy before ICSI‐AOA could be recommended as an appropriate option before ICSI‐AOA.     

Effect of sperm pooling with seminal plasma collected in breeding or nonbreeding season on Saanen goat sperm cryosurvival

The aim of this study was to determine the effects of both the removal of seminal plasma (SP) and the pre‐freezing addition of seminal plasma collected during the breeding or nonbreeding season on goat sperm survival after thawing. Semen samples were pooled. One aliquot of pooled semen was used as a control group. Four aliquots were then centrifuged, and the SP was removed in Group I, pipetted but not removed in Group II, removed and then pooled for animals collected in the breeding season in Group III and removed and pooled for animals collected in the nonbreeding season in Group IV. Group samples were frozen and then were assessed for rates of sperm motility, plasma membrane functional integrity hypo‐osmotic swelling test (HOST), defective acrosomes (FITC‐PSA), DNA fragmentation (TUNEL) and mitochondrial membrane damage (Rhodamine 123). The results showed that pre‐freezing addition of SP collected in breeding season maintained post‐thaw sperm characteristics at 0 hr better than SP removal group, but removing seminal plasma showed positive effects on spermatozoa, as incubation time increased to 5 hr. In conclusion, the pre‐freezing addition of seminal plasma did not maintain post‐thaw goat sperm characteristics as successfully as in the groups with seminal plasma removed after an incubation period.     

Effects of leptin on sperm count and morphology in Sprague‐Dawley rats and their reversibility following a 6‐week recovery period

Altered epididymal sperm count and morphology following leptin treatment has been reported recently. This study examined the effects of 42 days of leptin treatment on sperm count and morphology and their reversibility during a subsequent 56‐day recovery period. Twelve‐week‐old male Sprague‐Dawley rats were randomised into four leptin and four saline‐treated control groups (n = 6). Intraperitoneal injections of leptin were given daily (60 μg Kg^?1 body weight) for 42 days. Controls received 0.1 ml of 0.9% saline. Leptin‐treated animals and their respective age‐matched controls were euthanised on either day 1, 21, 42 or 56 of recovery for collection of epididymal spermatozoa. Sperm concentration was determined using a Makler counting chamber. Spermatozoa were analysed for 8‐hydroxy‐2‐deoxyguanosine and DNA fragmentation (Comet assay). Data were analysed using anova . Sperm concentration was significantly lower but fraction of abnormal spermatozoa, and levels of 8‐hydroxy‐2‐deoxyguanosine were significantly higher in leptin‐treated rats on day 1 of recovery. Comet assays revealed significant DNA fragmentation in leptin‐treated rats. These differences were reduced by day 56 of recovery. It appears that 42 days of leptin treatment to Sprague‐Dawley rats has significant adverse effects on sperm count and morphology that reverse following discontinuation of leptin treatment.     

Use of zona pellucida-bound spermatozoa as a natural selection in improvement of ICSI outcomes: A systematic review and meta-analysis

Zona pellucida (ZP)-bound spermatozoa have normal morphology and motility and can enhance the ICSI outcomes. Selection of zona pellucida-bound spermatozoa is recently considered to find functional spermatozoa for ICSI. This study reviewed the efficacy of ZP-bound sperm selection on the ICSI outcomes includes fertilisation rate, embryo quality, embryo transfer rate and clinical pregnancy rate. The databases searched include PubMed, Scopus and Cochrane databases up to January 2019. All research reports with full text and in English language that addressing the relation between ZP-sperm selection and ICSI outcomes were included. Fifty studies were suitable after screening of the 845 identified articles. After exclusions, five of these studies were included. Meta-analytic pooling of data indicated no association between the ICSI outcomes and ZP-bound sperm selection except a marginal effect on implantation rate. Eliminating one study indicated that ZP-bound sperm selection technique improves embryo quality, implantation rate and clinical pregnancy rate. This study revealed that ZP-bound sperm selection produces only a slight improvement in implantation rate. However, further studies with a large number of couples must be done to clarify the potential beneficial effect of ZP-bound spermatozoa on ICSI outcomes.     

Effects of glycerol,equilibration time and antioxidants on post‐thaw functional integrity of bovine spermatozoa directly obtained from epididymis

This work aimed to evaluate the effect of stabilisation times, glycerol concentration, and the catalase and superoxide dismutase supplementation of diluent on parameters of frozen‐thawed spermatozoa from epididymis of Nelore bulls: Experiment 1: spermatozoa diluted in Tris‐egg yolk with glycerol (3%, 5% or 7%) and stabilisation times (0, 2 or 4 hr at 5°C); Experiment 2: Tris‐egg yolk only, Tris‐egg yolk with catalase (CAT, 50 or 100 U ml^?1) or superoxide dismutase (SOD, 50 or 100 U ml^?1). Frozen‐thawed spermatozoa were evaluated for kinetic parameters, plasma membrane and acrosome integrity, mitochondrial activity and IVF capacity. ALH and BCF were affected (p < .05) by glycerol at 3% after 4‐hr equilibration time and 7% after 2‐hr equilibration time. Glycerol 3% had lower (p < .05) iPM and iAc after 4 hr. Glycerol 5% had greater (p < .05) hPMM after 4 hr and iAc after 2 hr than at 0 hr. SOD 100 U ml^?1 had lower (p < .05) linearity and wobble compared to control group. No was observed differences to fertilisation rate (p < .05) among groups. In conclusion, glycerol 5% in Tris‐egg yolk extender for 4 hr is suitable for the preservation of sperm kinetics and membrane integrity. CAT (50 and 100 U ml^?1) or SOD (50–100 U ml^?1) had no beneficial effects on sperm kinetics, plasma and acrosomal membrane integrity, mitochondrial activity or the capacity for IVF of frozen‐thawed spermatozoa from epididymis of Nelore bulls.     

Comparison and evaluation of capacitation and acrosomal reaction in freeze‐thawed human ejaculated spermatozoa treated with L‐carnitine and pentoxifylline

Cryopreservation is used to preserve the spermatozoa; however, it leads to a reduction in sperm quality. L‐carnitine (LC) influences sperm motility and preserves the sperm membrane and DNA integrity. The objectives of this study were to evaluate the protective effects of LC on the membrane integrity of normal human spermatozoa and compare it with pentoxifylline (PT) during cryopreservation. Thirty normal semen samples, prepared by swim‐up procedure, were divided into three aliquots: a control without any treatment and two experimental aliquots that were incubated in PT or LC for 30 min. All aliquots were cryopreserved and thawed after 48 hr. To evaluate the percentages of intact, acrosomal‐reacted and capacitated spermatozoa, lectin histochemistry and flow cytometry were performed by wheat germ agglutinin, peanut agglutinin and Con A. Statistical analyses were performed using ANOVA. LC supplementation elevated the percentage of noncapacitated spermatozoa compared with control and PT‐treated samples and the percentages of acrosomal intact spermatozoa compared with PT‐treated samples. PT pre‐treatment improved the motility but not membrane integrity. LC supplementation reduced the percentages of acrosomal‐reacted spermatozoa compared with the control and PT‐treated samples. Although LC did not improve motility, it protected the plasma membrane and acrosomal integrity. Therefore, LC may be the superior choice compared to PT for maintaining the sperm integrity.     

Effects of primary testicular damage on sperm DNA oxidative status and embryonic and foetal development

We evaluated the development of embryos generated from the fertilisation of oocytes with spermatozoa isolated from animals with primary testicular damage (PTD). Embryos derived in vivo or in vitro from oocytes fertilised with spermatozoa produced by PTD rats that had undergone surgical treatment for the PTD (group A1), or PTD rats (group A2), or control rats (group B) were cultured and transferred to recipients. At the end of the experimental period, the fertilisation potential of each rat was assessed in vitro (IVF trials). Sperm 8-oxodG/dG ratio (a marker of DNA oxidative status) was significantly larger in group A2 than in groups A1 and B. Blastocysts of the group A2 transferred to recipients demonstrated a significantly larger loss before implantation than transferred blastocysts of groups A1 or B. In addition, the proportion of implanted blastocysts that could not complete the intrauterine development was significantly larger in group A2 than in groups A1 and B. This study reveals a post-fertilisation detrimental effect in animals with PTD on the capacity of oocytes (fertilised either in vitro or in vivo ) to develop in vitro and implant after transferring them to recipients probably attributable to sperm DNA oxidative damage.     

Survival of buffalo bull spermatozoa: effect on structure and function due to alpha‐lipoic acid and cholesterol‐loaded cyclodextrin

Sperm survival depending upon integral membranes and function is imperative for fertilization. This study was designed to augment survival of buffalo spermatozoa using alpha‐lipoic acid (ALA) and cholesterol‐loaded cyclodextrin (CLC) during cryopreservation. Semen was frozen using 0, 0.5, 1, 1.5, 2 and 2.5 mmol L^?1 ALA (experiment 1) and ALA or CLC separately or together (experiment 2). Semen was assessed for post‐thaw motility, plasma membrane integrity (PMI), intact acrosome and plasma membrane (IACR‐IPM) and DNA integrity at 0, 1.5, 3 and 4.5 hr of incubation. In experiment 1, use of 0.5 mmol L^?1 ALA enhanced the sperm cryosurvival and post‐thaw longevity than other groups up to 4.5 hr of incubation, and this concentration of ALA was used in second experiment with CLC. The results revealed higher (p < .05) sperm survival function and time of sperm attributes due to use of ALA than CLC and control. However, the sperm quality did not improve (p > .05) when ALA was combined with CLC. In conclusion, survival of buffalo bull spermatozoa during freeze‐thawing and post‐thaw incubation can be enhanced more with ALA than CLC or control, followed by CLC than control. However, there is no synergistic effect on survival of buffalo bull spermatozoa due to ALA and CLC.     

An evaluation of chromatin condensation and DNA integrity in the spermatozoa of men with cancer before and after therapy

Cancer has been known for a long time to have a depressive effect on sperm number and quality. Cytotoxic agents and radiotherapy have also been shown to impair spermatogenesis. The aim of this study was to assess DNA integrity and chromatin condensation in the spermatozoa of men with cancer before and after treatment. Chromatin condensation was evaluated using flowcytometric assessment with propidium iodide, DNA integrity was determined using the comet assay. Thirty-three men with cancer (testicular cancer, lymphoma and leukaemia) and 14 men with proven fertility took part in the study. The study found that in men with cancer, the percentage of spermatozoa with highly condensed DNA was less than that of controls. DNA integrity when assessed using the comet assay was also reduced by cancer. Percentage head DNA intact and percentage of condensed chromatin in the spermatozoa of men with cancer after treatment were less than those in fertile men. This study, although small, does demonstrate a detrimental effect on chromatin condensation and DNA integrity of cancer and its treatment. These findings are important because of the potential effects impaired chromatin and DNA integrity could have on fertilization, blastocyst and embryo development.     

A new approach for cryoprotectant‐free freezing of goat epididymal spermatozoa

A cryoprotectant‐free method was successfully used for rapid freezing of goat epididymal spermatozoa. Lowering sperm volume may increase the temperature exchange rate and improve the freezing output of spermatozoa. The aim of this study was to compare two different packaging types [0.25 ml French straws (FS) and 96‐well immune plate (WIP)] for rapid freezing of goat epididymal spermatozoa. Eleven pairs of the goat testes were transferred to the laboratory; cauda epididymidides were dissected and sliced in TRIS‐BSA solution for 15 min and temperature 33–35 °C. Sperm concentration was adjusted to 20 × 10⁶ ml^?1, and the suspension was subjected to rapid freezing within FS or WIP. The volume of spermatozoa in WIP method was set at 25 μl. Sperm motility, viability and abnormalities, and sperm DNA integrity were compared between two devices. The results showed similar effectiveness of WIP and FS on post‐thaw sperm parameters. In conclusion, for cryoprotectant‐free rapid freezing of goat epididymal spermatozoa, it is recommended to use WIP instead of French 0.25 ml straws.